SUNRPC: Remove .conflen field from struct gss_krb5_enctype

Now that arcfour-hmac is gone, the confounder length is again the
same as the cipher blocksize for every implemented enctype. The
gss_krb5_enctype::conflen field is no longer necessary.

Tested-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

include/linux/sunrpc/gss_krb5.h

@@ -64,9 +64,6 @@ struct gss_krb5_enctype {
 	const char		*cksum_name;	/* crypto checksum name */
 	const u16		signalg;	/* signing algorithm */
 	const u16		sealalg;	/* sealing algorithm */
-	const u32		conflen;	/* confounder length
-						   (normally the same as
-						   the blocksize) */
 	const u32		cksumlength;	/* checksum length */
 	const u32		keyed_cksum;	/* is it a keyed cksum? */
 	const u32		keybytes;	/* raw key len, in bytes */

net/sunrpc/auth_gss/gss_krb5_crypto.c

@@ -610,6 +610,7 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 	struct encryptor_desc desc;
 	u32 cbcbytes;
 	unsigned int usage;
+	unsigned int conflen;
 
 	if (kctx->initiate) {
 		cipher = kctx->initiator_enc;
@@ -623,12 +624,13 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 		usage = KG_USAGE_ACCEPTOR_SEAL;
 	}
 	blocksize = crypto_sync_skcipher_blocksize(cipher);
+	conflen = crypto_sync_skcipher_blocksize(cipher);
 
 	/* hide the gss token header and insert the confounder */
 	offset += GSS_KRB5_TOK_HDR_LEN;
-	if (xdr_extend_head(buf, offset, kctx->gk5e->conflen))
+	if (xdr_extend_head(buf, offset, conflen))
 		return GSS_S_FAILURE;
-	gss_krb5_make_confounder(buf->head[0].iov_base + offset, kctx->gk5e->conflen);
+	gss_krb5_make_confounder(buf->head[0].iov_base + offset, conflen);
 	offset -= GSS_KRB5_TOK_HDR_LEN;
 
 	if (buf->tail[0].iov_base != NULL) {
@@ -744,7 +746,6 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
 	}
 	blocksize = crypto_sync_skcipher_blocksize(cipher);
 
-
 	/* create a segment skipping the header and leaving out the checksum */
 	xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
 				    (len - offset - GSS_KRB5_TOK_HDR_LEN -
@@ -801,7 +802,7 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
 		ret = GSS_S_BAD_SIG;
 		goto out_err;
 	}
-	*headskip = kctx->gk5e->conflen;
+	*headskip = blocksize;
 	*tailskip = kctx->gk5e->cksumlength;
 out_err:
 	if (ret && ret != GSS_S_BAD_SIG)

net/sunrpc/auth_gss/gss_krb5_mech.c

@@ -47,7 +47,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .sealalg = SEAL_ALG_DES,
 	  .keybytes = 7,
 	  .keylength = 8,
-	  .conflen = 8,
 	  .cksumlength = 8,
 	  .keyed_cksum = 0,
 	},
@@ -68,7 +67,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .sealalg = SEAL_ALG_DES3KD,
 	  .keybytes = 21,
 	  .keylength = 24,
-	  .conflen = 8,
 	  .cksumlength = 20,
 	  .keyed_cksum = 1,
 	},
@@ -90,7 +88,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .sealalg = -1,
 	  .keybytes = 16,
 	  .keylength = 16,
-	  .conflen = 16,
 	  .cksumlength = 12,
 	  .keyed_cksum = 1,
 	},
@@ -112,7 +109,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .sealalg = -1,
 	  .keybytes = 32,
 	  .keylength = 32,
-	  .conflen = 16,
 	  .cksumlength = 12,
 	  .keyed_cksum = 1,
 	},

net/sunrpc/auth_gss/gss_krb5_wrap.c

@@ -168,7 +168,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
 	struct page		**tmp_pages;
 	u32			seq_send;
 	u8			*cksumkey;
-	u32			conflen = kctx->gk5e->conflen;
+	u32			conflen = crypto_sync_skcipher_blocksize(kctx->enc);
 
 	dprintk("RPC:       %s\n", __func__);
 
@@ -261,7 +261,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, int len,
 	void			*data_start, *orig_start;
 	int			data_len;
 	int			blocksize;
-	u32			conflen = kctx->gk5e->conflen;
+	u32			conflen = crypto_sync_skcipher_blocksize(kctx->enc);
 	int			crypt_offset;
 	u8			*cksumkey;
 	unsigned int		saved_len = buf->len;